1. Field of the Invention
This invention concerns floating docks and is more particularly concerned with floating docks utilizing buoyant floats and having a utility passageway through which utility conduits are routed.
2. General Discussion of the Background
Floating boat docks are commonly constructed by securing a number of rectangular marine floats to each other. Boats are then moored alongside the floats, where it is desirable to provide them with utility services such as electricity, water, sewage, and telephone. Boat docks which supply such services have already been developed.
For example, U.S. Pat. No. 4,353,320 discloses a dock utilizing a marine float having a concrete casing completely surrounding a core of buoyant foam. A utility trench extends longitudinally along the float. One or more compression rods interconnect each longitudinal wall of the float to compressively load the float and enhance its strength. All of the dock's freeboard must also be provided by the float itself, therefore requiring a large, heavy concrete casing that has sufficient displacement to hold the deck of the float out of the water. Finally, the dock is structurally weak at the center of the deck because of the presence of the longitudinal trench in the float.
U.S. Pat. No. 4,318,362 shows a floating concrete dock having a deck portion with a plurality of buoyant floats immediately beneath the deck. The docks are cast with prestressed tendons extending longitudinally to maintain it under longitudinal compression.
U.S. Pat. Nos. 3,073,274 and 4,316,426 both disclose floating docks having decks spaced above floating members. Neither of these structures, however, place the floats and deck under horizontal compression. Absence of such compression allows the dock to bend under the influence of wave forces, eccentric or cantilever loads, and other influences.
Prior art docks have been made out of many materials, such as concrete and plastic. Although plastic components are resistant to salt water deterioration and are easy to manufacture, transport and assemble, they have not been widely accepted for use in dock construction. An example of such a prior art dock using plastic modules is the Thompson Anti-Twist Float manufactured by Thompson Floatation Inc. The Thompson dock includes a plurality of plastic modules each having a continuous, horizontal peripheral flange around an open top of the float. The float has a closed bottom and is filled with buoyant foam which is covered by a protective board. Each module is connected to the dock by placing a plurality of lag screws through the flange into a deck structure. Water leaks into the module through the joint between the deck and horizontal flange, which reduces freeboard of the dock. It is also difficult to provide ballast for the dock since any heavy material within the plastic module will increase its weight and tend to tear out the screws which secure the module to the deck.
U.S. Pat. Nos. 3,448,709 and 4,559,891 disclose docks having plastic floats and tie bars through the decks. Since the deck is molded on the float, no space is provided through which utility lines may pass. Moreover, a peripheral flange of the module in the '891 patent is subject to direct vertical tension which tends to tear the flange.
U.S. Pat. Nos. 3,179,076 and 4,041,716 also disclose docks having plastic modules, but the tie bars in these patents extend through vertical walls of the module below the deck. Ballasting such modules places a direct vertical tension on the module which risks tearing the unit.
It is accordingly an object of this invention to provide an improved floating dock having a utility passageway through which utility conduits may be placed.
Another object of the invention is to provide a dock which can be compressively loaded to enhance its strength and resistance to wave action.
Yet another object of the invention is to provide a rigidified floating dock which spans waves and can be easily transported.
Still another object of the invention is to provide a dock in which nails, screws, or other fasteners cannot work their way above the surface of the deck thereof under torsional forces.
Even yet another object of the invention is to provide a lightweight floating dock having substantial freeboard.
Another object of the invention is to provide a dock that can be easily refurbished, and also to provide a method for refurbishing existing docks.
Yet another object of the invention is to provide a wash space for debris in a floating dock structure.
Another object is to provide a floating dock structure capable of receiving a variety of deck surfaces.
A further object is to provide a floating dock structure wherein utility lines may be positioned in a fully open utility passageway prior to installation of a covering deck.
Another object of this invention to provide a floating dock which resists the corrosive influence of the water in which it is placed.
A further object is to provide a dock having modules which are under horizontal compression without being subject to direct vertical tensions, even when the modules are ballasted.
Even yet another object is to provide such a dock which does not allow unwanted water to seep into the modules.
Finally, it is an object to provide a dock comprised of modules which are easily stackable and liftable.
These and other objects of the invention will be understood more clearly by reference to the following detailed description and drawings.